Usually, a machine tool uses, when carrying out machining work for cutting a workpiece, such as boring work, with a cutting tool, such as a drill, a reamer or a center drill, a cutting tool chuck which fits a taper shank of a cutting tool or a tool holder in a tapered bore formed in a spindle of a machine tool serving as a component of the cutting tool chuck, and the spindle of the machine tool holding the cutting tool chuck is rotated to carry out desired cutting work for the workpiece.
In such a conventional cutting tool chuck, however, the clamping force which can be exerted on the shank of the tool holder or the cutting tool by the spindle is limited by a frictional force acting between the tapered bore of the spindle and the shank of the tool holder or the cutting tool, and accuracy in mounting the tool holder or the cutting tool is liable to be made unreliable by the fretting of the mating surfaces of the tapered bore of the spindle and the taper shank of the tool holder or the cutting tool. Therefore, It is difficult to achieve heavy cutting work, such as deep hole boring and face milling, accurately with a cutting tool held by the conventional cutting tool chuck.